Abstract: A localized clean air system for operating theaters and a method of supplying clean air to a localized region in such situations. A fan is connected to a delivery head, which has an outlet for directing inlet clean air to the localized region in a particular pattern. A streamlined body is positioned in the outlet so that, in use, the clean air flows around the body and is modified thereby to form, immediately downstream of the body, an inner region of low velocity air encircled by an outer region of higher velocity air. Preferably, the streamlined body is symmetrical about its axis and is aligned with the clean air flow, for instance by being centrally positioned in the air outlet. The streamlined body preferably comprises a rounded head and a tapered tail. A diffuser is disposed in the clean air flow upstream of the streamlined body to minimize turbulence in the air flow.